JPS5828211Y2 - Hentai-yoshi-gaisen-riyou-no-keikou-tai-kenshi-tsu-souchi - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device for detecting the presence of a phosphor by irradiating it with light from an ultraviolet lamp that flashes at a constant frequency.

In order to automatically cut sheets of paper or cloth or automatically detect defects such as scratches on the surface of wood or metal, light is irradiated onto the surface of these objects, and the reflected light is used for photoelectric conversion using phototransistors, etc. Conventionally, it has been widely used to detect check marks, surface gaps, etc. (hereinafter referred to as check marks, etc.) by receiving light into an element.

However, detection of check marks and the like using reflected light is easily affected by unevenness and coloration of the surface of the object, and detection is often difficult or impossible.

For example, when fabrics of various colors and textures are mixed, check mark detection for automatic cutting, check mark detection for cutting and removing defects on wood surfaces with various surface conditions, and polishing. An example of this is the detection of scratches on a metal surface.

Therefore, a method was devised to reliably detect check marks and the like even in such cases.

In other words, instead of using ordinary paint, dye, ink, etc., to mark a checkmark, etc., a fluorescent material is applied to the local area to be detected in advance.
When the phosphor is irradiated with ultraviolet light, the energy of the ultraviolet light is absorbed and visible light with a longer wavelength is emitted, which is used to detect check marks and the like.

In this method, since the irradiation light is invisible ultraviolet rays, the ultraviolet rays are only reflected from the surface of the object to be sandwiched, whereas visible light of a certain wavelength is emitted from the phosphor check marks, etc. be done.

Therefore, if an optical filter is used to allow only visible light to pass through, the condition of the surface of the object (with 9 different colors of unevenness) can be improved.
Checkmarks and the like can be detected very clearly without being affected by this.

To mark checkmarks etc. with fluorescent material, you can mark the surface of fabric or wood with ordinary fluorescent chalk, but there are also other special methods, such as marking them on the surface of fabric or wood at the weaving stage. One possible method is to weave threads with phosphor attached to them at predetermined positions.In order to find scratches on polished metal surfaces, first coat the entire surface with phosphor, and then weave the phosphor into the thread. Possible methods include wiping the body and leaving the phosphor only in the scratches.

The present invention has been made for the purpose of providing a phosphor detection device necessary for carrying out the above method.

The phosphor detection device consists of a light emitting section T and a light receiving detecting section R, the light emitting section including an ultraviolet lamp and a means for blinking the ultraviolet lamp at a constant cycle, and the light receiving detecting section detecting the ultraviolet rays. It includes an optical system consisting of an optical filter for cutting and a condensing lens, a photoelectric conversion element, and electric circuits for bandpass filtering, amplification, detection, etc., and is capable of handling the effects of ambient light surrounding the detection environment such as natural light and illumination light. This makes it possible to reliably detect fluorescent substances such as check marks without being affected by any interference.

Next, the configuration, operation, and effects of the present invention will be described with reference to the drawings showing one embodiment thereof.

FIG. 1 is a block diagram showing an outline of the phosphor detection device of the present invention, FIG. 2 is a circuit diagram showing an example of an actual circuit of the light emitting section T, and FIG. 3 is a block diagram showing an example of the actual circuit of the light receiving section R. FIG.

The outline of this apparatus will be explained with reference to FIG. 4 showing the output waveforms of each block in FIG. 1.

First, a DC-AC converter generates pulses with a constant period, and a lamp drive circuit differentiates the pulses to generate a drive output for the ultraviolet lamp 1 (this part will be explained in detail later).

) at a constant frequency (for example, about 5 KHz).
The surface of the specimen is irradiated with ultraviolet light (modulated ultraviolet light) that repeats brightness and darkness.

The above is the light emitting section T.

Now, the irradiated ultraviolet rays are reflected by the surface of the test object,
When a phosphor is present on the other side of the object, the phosphor absorbs ultraviolet light and emits visible light.

Therefore, the visible light emitted from the phosphor, the reflected ultraviolet rays, and the disturbance light are transmitted to the phototransistor 2 of the light receiving detection section.
However, in reality, the optical filter A is used to cut out ultraviolet rays and infrared rays, and only visible rays are allowed to be received by the phototransistor 2 (this part will be explained in detail later).

) The phototransistor 2 converts the optical signal into an electrical signal, and the bandpass filter circuit cuts out the electrical signal corresponding to ambient light such as natural light and illumination light, and only the electrical signal with the same frequency as the modulated ultraviolet light emitted from the light emitting part is generated. When the signal is extracted, amplified, and detected, as shown in Figure 4, a large output is obtained during the time when visible light emitted from the phosphor is being received, making it possible to detect the phosphor. can.

Furthermore, by integrating this output, shaping the waveform using a Schmidts circuit, and further amplifying it, it becomes possible to obtain a drive output for a relay or the like of an external control device.

Next, the optical systems of the light emitting section and the light receiving and detecting section R will be described in detail.

An example of using a phosphor that emits visible light (green) with a wavelength of around 550 nm when irradiated with ultraviolet light in the near-ultraviolet region (wavelength 320 to 380 nm) will be explained.

First, regarding the light emitting section, as an ultraviolet lamp having light emitting characteristics in the near ultraviolet region, a commercially available lamp (fluorescent chemical lamp) having a spectral energy distribution as shown in FIG. 5, for example, may be used.

The outline of the light emitting part is shown in FIGS. 6 and 1.

The UV lamp is removable, and the main part has a sealed structure.

Next, the optical system of the light receiving and detecting section will be described in detail with reference to FIG.

A phototransistor 2 is attached to one end of the case 7, and in front of it is an infrared cut filter 6, and further in front of it is a condensing lens 5 and a near ultraviolet cut filter 4.
, -order filter 3 is installed.

All of these filters can be selected from commercially available filters, and an example of their transmission characteristics is shown in Figure 9 with respective numbers assigned to each characteristic curve. It has maximum transmittance at a wavelength of 550 nm.

Now, the near ultraviolet light 10 irradiated from the ultraviolet lamp is reflected on the surface of the test object 80, but the phosphor 9 is on the surface of the test object.
is present, visible light around 550 nm from the phosphor1
1 is emitted.

Therefore, visible light 11 emitted from phosphor 9 reaches the light receiving section together with reflected near ultraviolet rays 12 and disturbance light such as natural light and illumination light.

However, since a near-ultraviolet cut filter 4 and an infrared cut filter 6 are installed in front of the phototransistor 2, only the visible part of the visible light 11 emitted from the phosphor and the disturbance light is collected by the condenser lens 5. The light is emitted and received by the phototransistor 2.

Note that if the near ultraviolet cut filter 4 is irradiated with ultraviolet light with a short wavelength, the near ultraviolet cut filter 4 itself has the property of emitting fluorescence, making it difficult to detect the desired phosphor 9. It is necessary to exclude short wavelength ultraviolet rays.

-order filter 3 is installed for this purpose.

In the end, the visible light 11 emitted from the phosphor 9 and the disturbance visible light are converted into an electrical signal 13 by the phototransistor 2, but as mentioned above, the electrical signal corresponding to the disturbance visible light is cut by the bandpass filter circuit. , visible light 1 emitted from the phosphor 9
Only the electrical signal corresponding to 1 will be obtained.

Therefore, if the present fluorophore detection device and the object to be measured are moved relative to each other while facing each other at a constant distance, it is possible to obtain a sufficiently large electrical signal only when the fluorophore is present. It is also possible to obtain the drive output of external control equipment if necessary.

As described in detail above, the present invention detects check marks, etc. by using visible light emitted from a phosphor when irradiated with ultraviolet rays. This method has the remarkable effect of being able to easily detect check marks and the like on the surface of a test object, which are difficult to detect with a detection device that uses reflection.

Furthermore, since modulated ultraviolet rays are used, it is easy to separate and exclude electrical signals of disturbance light, and there are also characteristics that there are very few restrictions on the usage environment.

Furthermore, since certain foods (for example, soups) have the property of emitting fluorescence when contaminated with bacteria, this device can be used to detect defects in these foods. It is something that you have.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an overview of the phosphor detection device of the present invention, FIG. 2 is a diagram showing an example of the electric circuit of the light emitting section, FIG. 3 is a circuit diagram of the light receiving detection section, and FIG. FIG. 5 is a diagram showing the output waveform of each block in FIG. The figure is a schematic diagram of the optical system of the light receiving and detecting section, and FIG. 9 is a transmission characteristic diagram of each optical filter in FIG. 8. 1... Ultraviolet lamp, 2... Phototransistor, 3... -order filter, 4...
... Near ultraviolet cut filter, 5 ... Condensing lens, 6 ... Infrared cut filter, 7 ...
...Case, T...Light emitting section, R...Light receiving detection section.

Claims (1)

[Scope of utility model registration request] A light emitting section T including an ultraviolet generating means that concentrates the distribution of spectral energy in the near ultraviolet region and a means that makes the ultraviolet generating means flicker at a certain period; an optical filter means that transmits only visible light; and a photoelectric conversion element. A phosphor detection device using modulated ultraviolet light consisting of two parts: a light reception detection section R including a bandpass filter circuit, an amplifier circuit, and a detection circuit.